<div dir="auto">My DMM has a capacitance setting. I use it regularly to measure capacitors for fans, air conditioner compressors and motors. It's a good tool.<div dir="auto">f</div></div><br><div class="gmail_quote"><div dir="ltr" class="gmail_attr">On Thu, Jun 20, 2019, 10:20 PM Chris Prata via Thursday <<a href="mailto:thursday@newsm.org">thursday@newsm.org</a>> wrote:<br></div><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
<div dir="ltr">
<div style="font-family:Calibri,Helvetica,sans-serif;font-size:12pt;color:rgb(0,0,0)">
A little update, even though I was looking for an example dead short capacitor for the EE #2 night, I did not know that leakage could be seen with a VOM, nor really familiar with a VOM. So, I looked that up and determined one should be on my bench.</div>
<div style="font-family:Calibri,Helvetica,sans-serif;font-size:12pt;color:rgb(0,0,0)">
<br>
</div>
<div style="font-family:Calibri,Helvetica,sans-serif;font-size:12pt;color:rgb(0,0,0)">
As luck would have it, someone was selling a lot of three Simpson 260's online for $10. And he was willing to mail them. They arrived today and the one good one with a calibration tag was actually a high accuracy 270-5! A<span style="color:rgb(0,0,0);font-family:Calibri,Helvetica,sans-serif;font-size:12pt">fter
replacing the batteries, its readings match the DMM for volts and ohms very closely of the few values I checked.</span></div>
<div style="font-family:Calibri,Helvetica,sans-serif;font-size:12pt;color:rgb(0,0,0)">
<span style="color:rgb(0,0,0);font-family:Calibri,Helvetica,sans-serif;font-size:12pt"><br>
</span></div>
<div><font color="#000000" face="Calibri, Helvetica, sans-serif"><span style="font-size:12pt">So
</span></font>thanks<font color="#000000" face="Calibri, Helvetica, sans-serif"><span style="font-size:12pt"> Dave for the reply below because it moved me (</span>and<span style="font-size:12pt"> my bench) forward.
<span id="m_-4343750501556420345🙂" title=":slight_smile:">🙂</span></span></font></div>
<div><font color="#000000" face="Calibri, Helvetica, sans-serif"><span style="font-size:12pt"><span title=":slight_smile:"><br>
</span></span></font></div>
<div><font color="#000000" face="Calibri, Helvetica, sans-serif"><span style="font-size:12pt"><span title=":slight_smile:">For the curious: <a href="https://simpsonelectric.com/products/test-equipment/vom-multimeters/270-5-270-5rt" target="_blank" rel="noreferrer">https://simpsonelectric.com/products/test-equipment/vom-multimeters/270-5-270-5rt</a></span></span></font></div>
<div><font color="#000000" face="Calibri, Helvetica, sans-serif"><span style="font-size:12pt"><span title=":slight_smile:"><br>
</span></span></font></div>
<div style="font-family:Calibri,Helvetica,sans-serif;font-size:12pt;color:rgb(0,0,0)">
<hr>
<br>
</div>
<div>
<div id="m_-4343750501556420345divRplyFwdMsg" dir="ltr"><font face="Calibri, sans-serif" color="#000000" style="font-size:11pt"><b>From:</b> David Crowell <<a href="mailto:ka1edp@yahoo.com" target="_blank" rel="noreferrer">ka1edp@yahoo.com</a>><br>
<b>Sent:</b> Wednesday, June 5, 2019 8:44 PM<br>
<b>To:</b> Thursday NEWSM; Chris Prata<br>
<b>Subject:</b> Re: [Thursday] Engaging evening task</font>
<div> </div>
</div>
<div>
<div class="m_-4343750501556420345x_ydpc82d950yahoo-style-wrap" style="font-family:Helvetica Neue,Helvetica,Arial,sans-serif;font-size:16px">
<div></div>
<div>
<div>
<div>Hi Chris,</div>
<div><br>
</div>
<div>The best way to check an electrolytic capacitor is to use a VOM, not a DMM. The VOM will measure the leakage of the cap and the one with the lowest ohm reading is what you want.
<br>
</div>
<div><br>
</div>
<div>First you need to find out which VOM lead is negative. With the old VOM I use (NRI), the Red lead is actually the negative lead when measuring resistance. This is from the VOM's internal battery. I have heard this is not unusual. Use your DMM to check
the polarity.</div>
<div><br>
</div>
<div>Next, set the VOM on it's highest resistance setting. Connect the VOM to the cap - negative to negative. The VOM will jump up to a low resistance as the cap charges and then slowly increase to a few megohms if the cap is good. Finding an electrolytic with
a dead short is pretty rare. <br>
</div>
<div><br>
</div>
Instead of putting a wire across a cap to simulate a short, you might want to use a low value resistor. If the radio is plugged into a plain power strip, you can use the power strips switch to turn the radio off quickly if needed. I wouldn't use a line suppression
power strip.</div>
<div><br>
</div>
<div>In the 60 years or so that I have been working on old radios, I've never used a light bulb as a line draw tester. For several years now, I have used a variac with an ammeter. If there is a vacuum tube rectifier, a solid state substitute needs to be used
at low line voltages. I will be at the Museum this Saturday.</div>
<div><br>
</div>
<div>73,</div>
<div>Dave, KA1EDP</div>
<div><br>
</div>
<div><br>
</div>
</div>
</div>
</div>
</div>
</div>
_______________________________________________<br>
Thursday mailing list<br>
<a href="mailto:Thursday@host194.hostmonster.com" target="_blank" rel="noreferrer">Thursday@host194.hostmonster.com</a><br>
<a href="http://host194.hostmonster.com/mailman/listinfo/thursday_newsm.org" rel="noreferrer noreferrer" target="_blank">http://host194.hostmonster.com/mailman/listinfo/thursday_newsm.org</a><br>
</blockquote></div>